/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef itkFiniteCylinderSpatialFunction_hxx
#define itkFiniteCylinderSpatialFunction_hxx

#include "itkFloatingPointExceptions.h"
#include <cmath>

namespace itk
{
template <unsigned int VDimension, typename TInput>
FiniteCylinderSpatialFunction<VDimension, TInput>::FiniteCylinderSpatialFunction()
{
  // a normalized {1,1,...1} vector is
  // { 1.0 / sqrt( VDim ), ... }
  const double orientationVal = 1.0 / std::sqrt(static_cast<double>(VDimension));
  m_Orientation.Fill(orientationVal);
  m_NormalizedOrientation.Fill(orientationVal);
  m_AxisLength = 1.0f; // Length of cylinder axis.
  m_Radius = 1.0f;     // Radius of cylinder.
  m_Center.Fill(0.0f); // Origin of cylinder}
}

template <unsigned int VDimension, typename TInput>
void
FiniteCylinderSpatialFunction<VDimension, TInput>::SetOrientation(const InputType _Orientation)
{
  itkDebugMacro("setting Orientation to " << _Orientation);
  if (this->m_Orientation != _Orientation)
  {
    this->m_Orientation = _Orientation;
    //
    // save normalizedOrientation, so it doesn't need to be recomputed
    // in every call of Evaluate.
    double norm = 0.0;
    for (unsigned int i = 0; i < VDimension; ++i)
    {
      norm += this->m_Orientation[i] * this->m_Orientation[i];
    }
    norm = std::sqrt(norm);
    if (norm == 0.0) // avoid divide by zero
    {
      itkExceptionMacro("Degenerate orientation vector " << this->m_Orientation);
    }
    for (unsigned int i = 0; i < VDimension; ++i)
    {
      this->m_NormalizedOrientation[i] = this->m_Orientation[i] / norm;
    }
    this->Modified();
  }
}

template <unsigned int VDimension, typename TInput>
auto
FiniteCylinderSpatialFunction<VDimension, TInput>::Evaluate(const InputType & position) const -> OutputType
{
  const double halfAxisLength = 0.5 * m_AxisLength;

  Vector<double, VDimension> pointVector;
  Vector<double, VDimension> medialAxisVector;

  for (unsigned int i = 0; i < VDimension; ++i)
  {
    pointVector[i] = position[i] - m_Center[i];
  }
  for (unsigned int i = 0; i < VDimension; ++i)
  {
    medialAxisVector[i] = m_NormalizedOrientation[i];
  }

  // if length_test is less than the length of the cylinder (half actually,
  // because its length from the center), than
  // the point is within the length of the cylinder along the medial axis
  bool saveFPEState(true);
  if (FloatingPointExceptions::HasFloatingPointExceptionsSupport())
  {
    saveFPEState = FloatingPointExceptions::GetEnabled();
    FloatingPointExceptions::Disable();
  }

  const double distanceFromCenter = dot_product(medialAxisVector.GetVnlVector(), pointVector.GetVnlVector());

  // restore state
  if (FloatingPointExceptions::HasFloatingPointExceptionsSupport())
  {
    FloatingPointExceptions::SetEnabled(saveFPEState);
  }

  if (itk::Math::abs(distanceFromCenter) <= (halfAxisLength) &&
      m_Radius >= std::sqrt(std::pow(pointVector.GetNorm(), 2.0) - std::pow(distanceFromCenter, 2.0)))
  {
    return 1;
  }

  return 0;
}

template <unsigned int VDimension, typename TInput>
void
FiniteCylinderSpatialFunction<VDimension, TInput>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "Lengths of Axis: " << m_AxisLength << std::endl;
  os << indent << "Radius: " << m_Radius << std::endl;
  os << indent << "Origin of Cylinder: " << m_Center << std::endl;
  os << indent << "Orientation: " << std::endl;
  for (unsigned int i = 0; i < VDimension; ++i)
  {
    os << indent << indent << m_Orientation[i] << ' ';
  }
  os << std::endl;
  os << indent << "Normalized Orientation: " << std::endl;
  for (unsigned int i = 0; i < VDimension; ++i)
  {
    os << indent << indent << m_NormalizedOrientation[i] << ' ';
  }
  os << std::endl;
}
} // end namespace itk

#endif
